WPF datagrid 'newitemplaceholderposition' is not allowed during a transaction begun by 'addnew'

Question

I have a tabControl on a WPF form.

In one of the Tab Items I have a User Control that contains a DataGrid which has CanUserAddRows="True". The

Answer 1

I have used holmes answer but didn't work for me properly. So I changed little bit.

Here is my solution:

First of all, because of I'm using MVVM, I added this codes to the datagrid:

Namespaces are these:

xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"

Then, I added this code to the ViewModel and set the DataGrid:

private DataGrid _dg { get; set; }

public void OnDataGridInitializingNewItem(object sender, InitializingNewItemEventArgs e)
{
    if (_dg == null)
        _dg = (DataGrid)sender;
}

After all, when needed, I ran this code:

_dg.CommitEdit();

Finally it works very well :)

PS: First, I had tried CancelEdit method instead of CommitEdit. It worked and I went to another view that opened like pop-up. When I finished what to do and return to the view, last added row was gone. But it was committed to the db. After re-open the view, it was there.